A number of supply voltages generally have to be provided in circuits and appliances in which it is intended to minimize the power consumption. These supply voltages are produced from a DC input voltage.
So-called DC/DC converters are known for effective conversion of DC voltages. A DC/DC converter can be used to produce any desired DC output voltage from a DC input voltage.
A number of DC/DC converters may be operated in parallel, in order to produce a number of DC output voltages. Owing to the large number of components required, this solution is costly, and also has the disadvantage that the switching losses in the individual DC/DC converters adversely affect the overall efficiency. Another possible way to produce a number of DC output voltages is to produce the highest of the required DC output voltages by means of a DC/DC converter, and to use series regulators to generate the further DC output voltages from the highest supply voltage. This solution is not as costly as the use of a number of DC/DC converters, but, owing to the voltage losses in the series regulators, a considerably reduced overall efficiency must be accepted.
Furthermore, it is already known for transformers with a number of windings to be used in DC/DC converters with a number of output voltages. This has the disadvantage, inter alia, of the large amount of space that is required for this type of DC/DC converter.